Proteinoids comprise small poly(amino acid) polymers prepared by thermal random condensation polymerization of various α-amino acids.
It is well known that polymers obtained by condensation polymerization mechanism possess a very broad molecular weight distribution (polydispersity index, Mw/Mn), commonly between 1.5-2.0 (T. C. Ward, J. of Chemical Education 58 (11), 867-879), and typically with mean molecular weight that falls within the lower end of the molecular weight range of typical biogenic proteins (4000-10,000 Da).
A well-designed polymeric drug delivery system, whether it is targeting the tumor site passively or actively, improves the therapeutic index of the drugs, their selective tumor accumulation, their time of exposure to the tumor vasculature (i.e. to the tumor endothelial cells), while reducing their toxicity.
International patent application publication no. WO 1994/028878 discloses proteinoid carriers and methods for their preparation and use as oral delivery systems for pharmaceutical agents are described, wherein the proteinoid carriers are soluble within selected pH ranges within the gastrointestinal tract and display enhanced stability towards at least one of photolysis or decomposition over time. WO 1994/028878 discloses the preparation of the proteinoid carriers from proteinoids having between 2 and 20 amino acids and having a molecular weight of between about 250 and 2400 daltons.